By-pass disconnect switch for circuit interrupters



E. J. FIELD Jan. 1, 1963 BY-PASS DISCONNECT SWITCH FOR CIRCUIT INTERRUPTERS Filed June 20, 1960 INVENTOR.

EVE/2577 J F/ZD hired This invention relates to disconnect switches in general and more particularly to a disconnect switch adapted to by-pass a circuit interrupter so that the circuit interrupter may be replaced, repaired, or inspected without being enegized and without interrupting service on the line.

For automatic circuit interrupters, especially of the automatic reclosing type, it is recommended procedure that the units be removed from the line periodically for routine examination and servicing. This procedure permits early discovery of deteriorating parts and encourages replacement of worn parts before the wear progresses to a point where it can cause failure of the unit. This inspection results in maximum protection per dollar of investment inclusive of service costs. Because of the periodic removal of the interrupters from distribution circuits for the purpose of routine maintenance, means for quickly and positively connecting and disconnecting the interrupters is highly desirable for this purpose.

The prior art has utilized hot line clamps, regulator bypass switches, disconnecting fuses and conventional hook operated disconnect switches. These methods have been found to entail excessive expense, provide inadequate insulation, and permit the hazard of operator error to be present. Hence, there is a need for a switch of economical construction that will positively perform the fuctions of disconnecting and by-passing the circuit interrupter while at the same time maintaining an insulation level equal to the rest of the equipment on the same line.

The basic concept of the instant invention is best described by considering a pie-sector switch blade which comprises a segment of a circular disk. The segment is pivoted at the apex of the angle formed by the two radial boundaries and this pivot point is electrically connected to the main line. The segment is pivoted through approximately its angular expanse with movement being limited in either direction by appropriately positioned stops. At the stop positions the segment is in engagement with one or the other of two stationary contacts spaced so that when the segment is moved from one stop to the other, engagement with one contact is made prior to disengagement from the other contact.

Two of these blades, insulated from each other but mechanically connected, provide a simple and positive means of inexpensive construction for a disconnect switch suitable for use with heavy duty interrupting devices.

In the embodiment of my invention to be hereinafter described in detail the segment is replaced by a main blade which carries an auxiliary blade. The auxiliary blade is either a resilient member rigidly mounted to the main blade or a rigid member resiliently mounted to the main blade. Each of the stationary contacts is provided with a latch means which engages the auxiliary blade. The latch means of one contact maintains contact with the auxiliary blade as the main blade separates from this contact and moves toward the other contact. Only at such time as the main blade is in engagement with the other contact does the latch means release the auxiliary blade permitting it to move to engagement with the latch means of the other contact.

Accordingly, a primary object of this invention is to provide a disconnect switch of relatively inexpensive contats atent struction which is adapted to by-pass a circuit interrupter so that the interrupter may be removed without interruptingservice on the power line.

Another object is to provide a novel disconnect switch which includes a pivoted blade movable into engagement with one of two stationary contacts prior to disengagement from the other of the contacts for both directions of blade movement.

Still anther object is to provide a novel disconnect switch construction including a blade means having an auxiliary blade whose movement is restrained by a contact latch means as the main blade moves away from this contact until such time as the main blade engages another contact whereupon the auxiliary blade moves to the other contact to be engaged by another latch means.

These as well as other objects of this invention shall become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE 1 is a side elevation of a disconnect switch constructed in accordance with the teachings of the instant invention.

FIGURE 2 is an end view of the switch of FIGURE 1 looking in the direction of arrows 2 FIGURE 3 is a schematic illustrating the disconnect switch of FIGURES 1 and 2 connected in a circuit.

FIGURE 4 is a schematic similar to FIGURE 3 illustrating a modification of the switch.

Now referring to the figures, switch 1% comprises parallel structural members 11, 12 secured to each other by cross-members l3, l4. Stand-ofis l5, 16 are mounted in spaced relationship upon member 11 and midway between stand-oils l5, 16 member 17 is mounted to member 1].. Que end of each of the insulator columns 1820 is mounted to members 15-17, respectively. The other ends of insulator columns 18, 19 carry stationary contact structures 21, 22, respectively while the other end of insulator column 20 carries pivot structure 23.

Elongated blade means 25 is pivotally mounted to structure 23 at pin 24 so as to be movable into and out of engagement with contact structures 21, 22 as will be hereinafter explained. Blade means 25 is comprised of two paraliel spaced conducting members 26, 27 maintained in spaced relationship by spacer 28 to form a jaW which receives portions 31, 32 of contact structures 21, 22, respectively. Blade means 25 further includes a resilient flexible member 29 mounted upon conducting standoff 30 to member 26. Contact structures 21, 22 include hook shaped latches 33, 34, respectively, which extend beyond portions 31, 32, respectively.

As blade means 25 is pivoted about pin 24 in a counterclockwise direction from the solid line position of FIG- URE l to the dotted line position thereof. Flexible member 29 remains in engagement with hook latch 34 at least until members 26, 27 engage contact structure portion 31. The stationary contact structures 21, 22 are so positioned and the lengths of members 26, 27 and 29 comprising blades means 25 so proportioned that after members 26, 27 engage structure portion 31 and before reaching the dotted line position of FIGURE 1, flexible member 2? is free of book latch 34 so that member 2 moves rapidly into alignment with members 25, 27 over the hook tip of latch 33. The pins 37, 38 which mount latch 33 to portion 31 maintain these two elements in spaced relationship so that member 26 may fit therebetween and pin 38 may act as a positive stop for blade means 25.

In a similar manner, as blade means 25 is pivoted clockwise from the dotted line position to the solid line position of FIGURE 1 members 26, 27 first engage contact structure portion 32 with flexible member 29 being restrained by hook latch 33. By the time member 26 engages pin 39 flexible member 29 is moved free of latch 33 and is moved into alignment with member 26 to the solid line position of FEGURE 1 into engagement with latch 34.

The portion of switch it hereinbefore described is designated as switch 46) in FIGURE 4 and is illustrated as being connected to bus sections 41, 42 as well as to one terminal 43 of an electrical protective device 4 lsuch as an automatic recloser or other type of circuit interrupter. Bus il is connected to pivot structure 23 while bus 42 is connected to stationary contact structure 21, and device terminal 43 is connected to stationary contact structure 22. The other terminal 4 5 of device a4 is connected to bus 42 by a line clamp 46 of a type well known to the art.

With switch 46 in the position illustrated in FIGURE 4, device 44 is connected in series between buses 41, 42. If it is desired to replace or inspect device 44 this may be done without interrupting the connection between buses 41, 42 by operating switch 40 so that blade means 25 engages stationary contact structure 21. Prior to complete disengagement of blade means 25 from stationary contact structure 22 blade means 25 engages stationary contact 1 3i and at this time the section 47 of bus 42 shunts device 4-4. Thereafter, blade means 25 completely disengages stationary contact 22 thereby disconnecting device terminal 23 from bus 41. At this time no current passes through line clamp 46 so that it may safely be disconnected from bus 42 to completey isolate device 44.

The portion of switch hereinbefore described has been limited to elements which are mounted upon structural member ill. The elements of switch 10 mounted to structural member 12 are substantially identical to members hereinbefore described so that corresponding reference numerals will be utilized therefor Without further description except that the reference numerals for elements mounted to structural member 12 will be provided with a prime symbol.

Insulator column 49 is connected between blade means 25 and 25 to provide an insulating mechanical connection therebetween. Pull ring 50 is connected to insulator 49 at the mid-point thereof to provide an element engageable by a hook so that switch It) may be hook stick operated. Thus, it is readily apparent that blade means 25 and 25' will operate in unison insofar as their portions 26, 27 are concerned. It is to be noted that there is no element mounted to structural member 12 which corresponds to stationary contact structure 21.

Switch 10 is shown connected in a circuit in cooperation with device 44 as shown in FIGURE 3. Jumper strap 52 is connected between stationary contact 21 and pivot structure 23' to which bus 42 is also connected. Bus 41 is connected to pivot structure 23. Device terminals 43, 45 are connected to stationary contacts 22, 22', respectively.

As shown in FIGURE 3, device 44 is connected in series between buses 41, 42. In order to disconnect device 44, switch it is moved from the solid line position of FIGURE 1 to the dotted line position thereof through a counterclockwise movement of blade means 25, 25. As this occurs, members 25, 27 engage portion 31 of stationary contact structure 21. During this period flexible members 29, 29 are restrained by hook latches 34, 34, respectively, so that device 44 is isolated from buses 41, 42.

For reverse movement of blade means 25, 25' members 25, 27 engage portion 32 and members 26, 2'7 engage portion 32' prior to the release of flexible member 29 by hook latch 33. Until such time as latch 33 releases member 29 strap 52 shorts device 44. 7

Thus, this invention provides a disconnect switch that provides means for speedily disconnecting protective devices from distribution circuits with economy and safety while at the same time continuing electric service to the load side of the line circuit interrupter.

While there has hereinbefore been described a blade means including a flexible member, it should be obvious to those skilled in the art that my invention can be carried out utilizing a blade means comprising a rigid member resiliently mounted.

Although I have here described preferred embodiment of my novel invention, many variations and modifications will now be apparent to those skilled in the art, and I therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

I claim:

1. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means being constructed with a main blade and an auxiliary blade; said contacts being spaced from each other such that said main blade when moving from said first position to said second position engages said second contact prior to disengagement of said auxiliary blade from said first contact.

2. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means being constructed with a main blade and an auxiliary blade; said contacts being spaced from each other such that said main blade when moving from said first position to said second position engages said second contact prior to disengagement of said auxiliary blade from said first contact, said main blade when moving from said second position to said first position engages said first contact prior to disengagement of said auxiliary blade from said second contact.

3. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second con tact and out of engagement with said first contact; said blade means including a first and second portion; said first portion engaging said second cont ct prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said secondposition.

4. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement or" said second portion from said second contact upon movement of said blade means from said second to said first position. i

5. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first portion to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position.

6. An electric switch comprising a first and a second contact insulated from each other, blade means movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first portion to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position; said second portion comprising a flexible member.

7. An electric switch comprising a blade means pivotally mounted at one end thereof, a first and a second contact spaced from one another and operatively positioned to engage the other end of said blade means upon pivotal movement thereof from a first to a second position; said blade means when in said first position being in engagement with said first contact and out of engagement with said second contact; said blade means when in said second position being in engagement with said second contact and out of engagement with said first contact; said blade means being constructed and said contacts being spaced from each other such that said blade means when moving from said first position to said second position engages said second contact prior to disengagement from said first contact and said blade means when moving from said second position to said first position engages said first contact prior to disention; said blade means when in said first position being in engagement with said first contact and out of engagement with said second contact; said blade means when in said second position being in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said sec ond to said first position.

9. An electric switch comprising a blade means pivotally mounted at one end thereof, a first and a second contact spaced from one another and operatively positioned to engage the other end of said blade means upon pivotal movement thereof from a first to a second position; said blade means when in said first position being in engagement with said first contact and out of engagement with said second contact; said blade means when in said second position being in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position.

10. An electric switch comprising a blade means pivotally mounted at one end thereof, a first and a second contact spaced from one another and operatively positioned to engage the other end of said blade means upon pivotal movement thereof from a first to a second position; said blade means when in said first position being in engagement with said first contact and out of engagement with said second contact; said blade means when in said second position being in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon-move ment of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position; said second portion comprising an elongated flexible member mounted at one end thereof to said first portion with the other end of the flexible member being engageable by said latch means of both of said contacts.

11. In combination a first bus, a second bus, an interrupter device for electrically connecting said buses to each other; first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, a second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with Said second contact and out of engagement with said first contact; said blade means being constructed and said contacts being spaced from each other such that said blade means when moving from said first position to said second position engages said second contact prior to disengagement from said first contact and said blade means when moving from said second position to said first position engages said first contact prior to disengagement from said second contact.

12. in combination a first bus, a second bus, an interrupter device for electrically connecting said buses to each other, first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, a second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said. first portion acme-e2 engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position.

13. In combination a first bus, a second bus, an interrupter device for electrically connecting said buses to each other, first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, at second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position.

14. In combination a first bus, a second bus, an interrupter device for electrically connecting said buses to each other, first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, a second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position; said second portion comprising an elongated flexible member mounted at one end thereof to said first portion with the other end or" the flexible member being engageable by said latch means of both of said contacts.

15. In combination a first bus, a second bus, an interrupter device for electrically connecting said buses to each other; first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, a second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second Contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means being constructed and said contacts being spaced from each other such that said blade means when moving from said first position to said second position engages said second contact prior to disengagement from said first contact and said blade means when moving from said second position to said first position engages said first contact prior to disengagement from said second contact; said first means comprising a third contact and a blade means one of which is electrically connected to said first bus and the other of which is connected to another terminal of said interrupter device; said first and said third contacts being of substantially identical construction; said blade means of both said switch and said first means being of substantially identical construction and being ganged for simultaneous operation whereby engagement and disengagement of both of said blade means with their associated said first and said third contacts occurs simultaneously.

16. In combination a first bus, a second bus, an inter-- rupter device for electrically connecting said buses to each other, first means for selectively connecting said device to said first bus, and an electric switch for selectively connecting said device to said second bus; said switch comprising a first contact electrically connected to said first bus, 21 second contact electrically connected to a terminal of said interrupter device, and a blade means electrically connected to said second bus; said blade means being movable from a first position in engagement with said first contact and out of engagement with said second contact to a second position in engagement with said second contact and out of engagement with said first contact; said blade means including a first and a second portion; said first portion engaging said second contact prior to disengagement of said second portion from said first contact upon movement of said blade means from said first position to said second position; said first portion engaging said first contact prior to disengagement of said second portion from said second contact upon movement of said blade means from said second to said first position; each of said contacts having latch means associated therewith operatively positioned and constructed to restrain movement of said second portion until said first portion has moved to a predetermined position; said second portion comprising an elongated flexible member mounted at one end thereof to said first portion with the other end of the flexible member being engageable by said latch means of both of said contacts; said first means comprising a third contact and a blade means one of which is electrically connected to said first bus and the other of which is connected to another terminal of said interrupter device; said first and said third contacts being of substantially identical construction; said blade means of both said switch and said first means being of substantially identical construction and being ganged for simultaneous operation whereby engagement and disengagement of both or said blade means with their associated said first and said third contacts occurs simultaneously.

' References Qi'ted in the file of this patent UNITED STATES PATENTS 

1. AN ELECTRIC SWITCH COMPRISING A FIRST AND A SECOND CONTACT INSULATED FROM EACH OTHER, BLADE MEANS MOVABLE FROM A FIRST POSITION IN ENGAGEMENT WITH SAID FIRST CONTACT AND OUT OF ENGAGEMENT WITH SAID SECOND CONTACT TO A SECOND POSITION IN ENGAGEMENT WITH SAID SECOND CONTACT AND OUT OF ENGAGEMENT WITH SAID FIRST CONTACT; SAID BLADE MEANS BEING CONSTRUCTED WITH A MAIN BLADE AND AN AUXILIARY BLADE; SAID CONTACTS BEING SPACED FROM EACH OTHER SUCH THAT SAID MAIN BLADE WHEN MOVING FROM SAID FIRST POSITION TO SAID SECOND POSITION ENGAGES SAID SECOND CONTACT PRIOR TO DISENGAGEMENT OF SAID AUXILIARY BLADE FROM SAID FIRST CONTACT. 